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The 2000 Volkswagen Lupo used start-stop to achieve a fuel economy of 75 mpg in Europe on a diesel engine. Manufacturers haven't brought the tech to non-hybrids in the U.S., due to flaws in the EPA's fuel economy testing.  (Source: Cars Plus Plus)
EPA is finally considering looking at the real value of stop start

Fuel economy ratings are supposed to provide an estimate of the vehicles' real-world performance, helping customers determine how efficient the vehicle is.  Unfortunately, the ratings are only as good as the tests that determine them, and in the U.S. Environmental Protection Agency's case, those tests aren't very good.

One significant oversight is stop start technology.  Overseas stop-start technology is featured on a host of models, including the Audi A3 TDI, BMW 1-Series, BMW 3-Series, Mazda 2, Mini Cooper, Toyota Yaris.  The technology is somewhat expensive -- it's about $500 extra to install -- however, it's more than worth it, providing fuel economy gains of around 7 percent.

The EPA's flawed test cycle, though, currently only includes one stop so the tech only earns automakers a 0.1 or 0.2 mpg increase in the official EPA mileage estimates, despite much larger real world gains.  Without the extra rating to justify the extra costs, manufacturers simply haven't been importing the tech on U.S. models. 

Currently, the only vehicles to feature the tech are hybrids such as the Toyota Prius, Honda Insight, Chevrolet Malibu Hybrid and BMW ActiveHybrid X6, as their electric systems allow the tech to be implemented at a much lower costs.  The net result is that at the end of the day, the U.S. is trailing the rest of the world in fuel economy.

Still the allure of models like the Volkswagen Lupo, which received an estimated 75 mpg, keep customers demanding that the EPA reconsider stop-start.  Robert Davis, Mazda's top product-development executive in North America, comments, "In Japan, we're seeing anywhere from 7 to 9 percent fuel economy gains from it. That's a jump from 33 to 37 miles per gallon in a metro environment."

Audi of America spokesman Christian Bokich complains, "We did not realize any savings in U.S. EPA estimates based on required testing cycles."

The EPA may finally be coming around and may try to fix its flawed test procedure.  It's taking public comment on stop-start technologies, currently, and will look to announce new procedures in April.  Those procedures could finally include a test with more stops.  Mazda is urging automakers to join together to lobby the EPA to give stop-start its just rewards.  While this is obviously a matter of personal interest to the company, it's also important industry wide, and to U.S. consumers.



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RE: I dont see the fuss
By Pneumothorax on 12/30/2009 12:19:22 PM , Rating: 3
BTW, the reason I keep bringing up the electric powered A/C up, is that here in hot southern CA, you're basically running the A/C up to 9 months of the year. This would negate this start-stop until the next gen of cars when they can switch over to revamped A/C Units. Remains to be seen if the electric compressors can push the same amount of BTU's as the belt driven ones.


RE: I dont see the fuss
By sinful on 12/30/2009 12:43:47 PM , Rating: 2
quote:
BTW, the reason I keep bringing up the electric powered A/C up, is that here in hot southern CA, you're basically running the A/C up to 9 months of the year. This would negate this start-stop until the next gen of cars when they can switch over to revamped A/C Units. Remains to be seen if the electric compressors can push the same amount of BTU's as the belt driven ones.


My girlfriend's 4-banger Hyundai doesn't put out much heat or cooling when just running idle (but when you give it gas it "comes back").
(i.e. there is a definite difference in heating/cooling ability when the engine is running idle vs. when you're going 50mph).

I don't think that's an intended feature but that's how it works.

It's essentially the same effect if I turn off my AC/Heater and just run the vent temporarily (i.e. residual cold/heat).

I bet most people experience a similar effect and just don't realize it, and the same would be true here - even if the heater or cooling is only running at 50% capacity most people won't notice unless you're stuck in traffic for a LONG time.


RE: I dont see the fuss
By mdogs444 on 12/30/2009 1:39:41 PM , Rating: 2
quote:
I don't think that's an intended feature but that's how it works.

Hyundai, Kia, Daewoo...

That's not a defect, that's an enhancement...


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